For activities there a wrist measurement is difficult we developed the VIITA ECG.
When running, for example, vibrations sometimes make accurate measurement difficult. Especially for running units, it helps to set the band as tight as possible so that the sensor does not lift off the skin. When cycling, it is the pressure on the wrist that makes blood supply more difficult and thus makes wrist measurement more difficult. The VIITA ECG is specially designed for people who want to measure their pulse accurately on the BPM.